I think this is an OS question. I have an HP Pavilion ze4145 with an AMD Athlon XP 1800+ processor. My laptop has been running a bit slow lately, with certain programs taking up way too much resources when I look at them through Task Manager. When I right click and look at the properties of My Computer, the bottom right corner, which usually shows some of the system specs (specifically the processor) will show me at least three different processor speeds at any given time. Sometimes, it tells me I have a 654MHz processor, sometimes a 791MHz processor, and sometimes the correct speed of 1.52 GHz. Does anyone know what might be going on? I've run Ultimate Troubleshooter, Norton Anti-Virus, etc. and nothing is found. Plus, when I try to run either Ad-Aware or Spybot, both of the programs end up taking up too much resources and lock up.

it's very common for laptop processors to down clock when they need to save power or reduce heat. It's something that Intel has been doing for years, where AMD only started 3 years ago... Intel used to call is speedstep. Anyway, when you don't need all that power the chip can do, it slows down to save juice.
This should be configurable, but I havn't seen an AMD one before, so I can't tell you where to look..